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Welcome to AX84® the base camp for tube (valve) electronics hobbyists.

AX84 exists to provide:

1) A great environment to learn about music-related electronics in general. AX84 is a place where those with experience are interested in helping diligent beginners who are willing to do their homework.

2) A place where those with more experience can field their ideas to peers and get useful feedback.

3) An environment that respects the past, but is not enslaved by it. INNOVATION IS GOOD (and it didn't die in the 1950s.) There are new things under the sun every day. Move the ball forward!

Our HUGE discussion area is under 'Discussion Forum' to your left.

We are hard at work improving the site- check back often!

Recent Forum Threads
"Bridge rectifier with zener B+ lowering and bias"
Posted By AneirinE on 03/26/2015
I'm building an amp with an EL84 poweramp. The PT doesn't have a CT on the high voltage secondary so I am using a bridge rectifier. The PT doesn't have a bias tap so I thought I could try the AC coupl...

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"Tonestacks. "
Posted By Alva Goldbook on 03/25/2015
I've been pondering tone stacks lately, and it rather bugs me that so many amps have used the Fender/Marshall tone stack. Because, in all honesty, it's a rather lousy circuit. The performance of the m...

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"Udating Ampeg Gemini II... how far can I go to keep vintage valu"
Posted By CChurchill on 03/25/2015
Firstly, I need to convert the power cord to a 3-prong earth grounded cord. I was going to just run a 3-prong through the same opening as the previous power cord. Since this modification is pretty muc...

Discuss this entry
""Raffler" DC drive (mod) schematic"
Posted By proton45 on 03/24/2015
Hello all, and thanks (in advance) for any help that you can give me...
I have used the "search feature", but I dont seem to be able to find a working link, that will take me to the "Raffler mod s...

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"Converting Roberts Tape Deck to P1"
Posted By vonholt on 03/24/2015
so last summer I scored a Roberts 90c tape machine and the accompanying 901 amp. After messing with the 901 amp and studying the schematics I thought this could be a good conversion to a P1. But this ...

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Updates: Fri, Mar 27th, 2015 @ 03:33:06
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Site News

2014-10-21: Be sure to check out our discussion forum using the link on the left..

2014-10-20: The Treasure Fleet is on the way to Rio De La Hacha with a fortune in gold!

We're looking for media clips of recent builds... please stop by the forum and respond to the thread.

2008-10-4: Archived Projects section is functional again.

2008-9-18: RSS Feeds for the forum have been up for a while, but not advertised...
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2008-6-26: Want to participate in our discussion forums? You are welcome to read and lurk as you like. If you think you'd like to post with regularity, please sign up for an account.

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